Sectional-type inductance coil



, 1,621456 March 15,1927. w W. BROWN ET AL 1,

v SECTIONAL TYPE INDUCTANCE -COIL Filed April 25, 1925 Y Inventohsf x WiiHam WQBTOWTT dssefiryBLove, v

b5 JV Thar Attefl eg.

Patented Mar. 15, 1927.

UNITED STATES 1,621,456 PATENT OFFICE.

WILLIAM W. BROWN AND JOSEPH E. LOVE, OF SCHENECTADY, NEW YORK, ASSIGNORS TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

SECTIONAL-TYPE INDUCTANCE COIL.

Application filed April 25, 1925. Serial No. 25,914.

Our present invention relatesto the construction of induct-ances and more particularly to inductances which are especially adapted for use in radio signaling systems of high power.

()ne of the objects of our invention is to provide a simple construction for an inductancc coil which is adapted for use with large currents and high voltages. A further object of our invention is to provide an improved type of coil supporting means.

The novel features which we believe to be characteristic of our invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation together with further objects and advantages thereof will best be understood by reference to the following disclosure taken in connection with the accompanying drawing in which Fig. 1 is a plan view of a coil constructed in accordance with our invention.

Fig. 2 is a cross sectional view, partly broken away, of a portion of the inductor.

As shown on the drawing, 1 indicates a hollow. cylindrical supporting member made of hardened plastic or vitreous material such as porcelain and having a length which is relatively small in comparison with its diameter. Each cylindrical member is provided at one end with an inwardly and downwardly directed flange 2, and an outwardly extending ledge 3. The successive cylindrical members are arranged to fit artially within one another as indicated in ig. 2 and mica or other insulating cushions 10 are inserted between the successive sections. I

Mounted on each ledge 3 are a plurality of insulators 4. The insulators are substantially triangular in longitudinal, vertical cross section, and are provided on their up-- per and lower sides with conductor retainmg grooves 5 and 6 in which conductor 7 may be wound. The base portions of the insulators 4 rest on the ledge 3 and are curved to fit snugly against the wall of memher 1. A thin cushion of mica or other insulation 8 is inserted'between members 1 and w 4. While winding the conductor each insulator may be temporarily held in the position shown on the drawing by means of a strap which passes around member 1 and a through a slot 9 in each of the plurality of insulators 4 mounted on member 1.

In winding the conductors upon the spacng blocks or insulators 4 the conductor 7 s wound inthe top series of grooves startmg at the point 11 and progressing outward until the last groove of the top series is reached. The conductor 7 is then carried down to the outer groove on the lower side of the next insulator. The conductor 7 is then wound progressively inward until the last groove on the lower side is reached. The conductor is then carried down to the inner top groove of the next insulator of the series and so on until the end of the coil is reached. The connection between the inner lower conductor on one set of insulators and its inner top conductor on the succeeding lower insulators may be made by means of a connector as indicated at 12.

When the coil is wound in this way, it will be noted that the maximum potential developed in the coil during operation, between the two adjacent outer turns carried by any insulator, will be the potential developed in a single turn of the conductor, while the maximum potential developed between the two inner turns carried by any insulator will be the potential developed in 16 turns. By making the insulators of triangular form the spacing between the two inner turns carried by each insulator is made enough greater than the spacing between the two outer turns to take care of the greater potential developed between the two inner turns. Distributed capacity of the coil is also reduced by this expedient. Similarly the spacing between the outer turns on the lower side of one series of insulators and the top of the next series below ais made greater than the spacing between the inner turns to take care of the increased potential.

It will also be observed that the conductor grooves on the lower sides of the insulators are in staggered relation to the grooves on the upper side so that the turns of the conductor on the lower side are not directly below the turns on the upper side of the insulator. This expedient. increases the spacing between the turns and also reduces the tendency to theformation'of partial short circuits of turns which might occur under certain conditions.

Coils, may be wound on the insulators shown in a variety of ways. The conductors may be wound in every groove, as shown turns.

been Wound on the insulating support 4, the

temporary strap may be removed if desired. The insulators will then be rigidly held in position on ledge 3 and against the main body portion of member 1 by the tension of conductor members 7 and 8 alone. With the 1 construction shown it will be noted that the only metal present in the entire structure is the conductor itself, so that the losses in the coil from metal fittings are completely eliminated.

By the provision of a flange portion 2 of lesser diameter than the main body portion of member 1 so that the flange fits on the inside rather than the outside of the adjacent lower section, the coils on the adjacent sections may be placed closer to one another than would otherwise be the case, giving a maximum mutual inductance between ad jacent coils, and thus increasing the efficiency of the inductor.

Nesting one cylindrical section within the other enables the sections to be held firmly in position, provides a ready means for changing the total inductance of the complete coil and gives a! compact arrangement whereby a very high inductance suitable for use at high power radio frequencies may be obtained.

\Vhile the arrangement shown is intended primarily for use indoors, and at high power radio frequencies it is also suitable for outdoor use under certain conditions of loading, and also for use in circuits other than high frequency circuits, and in which a coil of high inductance and high voltage insulation is required.

i \Vhat we claim as new and desire to secure by Letters Patent of the United States, is,

.1. In combination a plurality of super- The great posed hollow flanged members, one fitting partially within another and a plurality of insulators mounted on said members and extending outwardly therefrom.

2. An inductance coil comprising a hollow, substantially cylindrical member, the length of which is small compared with its diameter, an integral ledge adjacent one end thereof, a plurality of insulators mounted on the ledge, said insulators being provided 3. An inductance coil comprising a plurality of interlocking units each of said units comprising a hollow, .vitreous memberhaving an outwardly extending integral flange adjacent one end thereof, and a plurality of radially extending insulators detachably mounted on the flange, each of said insulators being provided with grooves, a winding in the grooves adapted to hold the insulators in position on the ledge and against the hollow member.

4. In combination, a plurality of superposed hollow flanged members, one fitting partially within the other, an integral flange on each of said members, and a plurality of insulators detachably mounted on said flanges and extending radially outward therefrom, said insulators being provided with a plurality of grooves adapted to sup port a winding.

5. In combination, a hollow vitreous member provided at one end thereof with an outwardly extending ledge and an inwardlyand downwardly extending flange, a plurality of radially extending insulators detachably with grooves, and a winding in the grooves.

mounted on the ledge, the insulators being provided with grooves, means whereby the insulators may be tem 'iorarily heldin position on the ledge and a winding mounted in the grooves of the insulators and adapted to hold the insulators in position on the ledge and against the vitreous member.

In witness whereof, WILLIAM IV. Bnowx has hereunto set his hand this 21st day of April, 1925, and JOSEPH E. Love has hereunto set his hand this 23rd day of April,

IVILLIAM IV. BROWN. JOSEPH E. LOVE. 

